A scientific method has been developed to measure the condition of Tasmanian rivers and streams, called the Tasmanian River Condition Index (TRCI).

TRCI has been designed for use in the range of river systems throughout Tasmania. It enables assessment of four aspects (or sub-indices) of condition:

• Aquatic Life – fish, macro-invertebrates and algae.
• Streamside zone – riparian or riverine vegetation.
• Hydrology – flow patterns and quantity.
• Physical Form – physical character of the channel, bank and bed material.

Condition is assessed by comparing the current river condition to pre-European condition. Sites are selected randomly throughout the catchment. The project was managed by NRM South and Earth Tech, in collaboration with NRM North and the Department of Primary Industries and Water.